The present embodiments relate to a radiation therapy device having an imaging unit, which is used principally for the treatment of tumor diseases. With the aid of the imaging unit, the anatomy of a patient to be treated may be displayed.
Radiation therapy devices are used for the treatment of tumor diseases, for example. Radiation therapy devices generally generate a beam of therapeutically effective X-rays (e.g., megavolt (MV) X-rays), which is directed at the region to be irradiated in a patient. Instead of X-rays, other therapeutically effective beams may be used (e.g., electron beams or beams of other charged particles).
In order to irradiate the region to be irradiated as precisely as possible and to avoid damaging surrounding tissue, it is important that a patient is positioned as precisely as possible with respect to the treatment beam. For this purpose, a method for performing an imaging process, which enables a patient to be monitored before or during a radiation therapy session, is known.
In this situation, the imaging can be implemented with the aid of X-rays which, originating from a radiation source, are directed onto the patient to be examined and are subsequently detected by a radiation detector. Generally, the X-rays that are used for imaging purposes have a considerably lower energy than those X-rays that are used for the therapy. Such diagnostic X-rays are also referred to as kilovolt (kV) X-rays. A method, however, is also known for using the therapeutically effective MV X-rays for imaging purposes.
Different arrangements are known with regard to how diagnostic radiation sources and diagnostic radiation detectors can be arranged in a radiation therapy device.
A method is thus known, for example, for using an electronic portal imaging device (EPID) in order to register two-dimensional images from a viewing direction that corresponds to the therapy beam path. Two-dimensional X-ray images or fluoroscopy images can likewise be used for position checking.
Using three-dimensional imaging such as, for example, cone beam computer tomography (CT) or conventional CT is also known.
Different methods are also known for monitoring the movement of a patient during a therapy session. This monitoring can be implemented, for example, with the aid of two-dimensional fluoroscopy images by monitoring internal landmarks or implanted markers (e.g., “fiducial markers”) with the aid of two-dimensional imaging in real time and/or with the aid of an external movement signal.